You could try nair, but that stuff smells like sh*t and is uncomfortable and itchy so I would not recmend it. Good Luck.
MEMO:  2 ALL  "NEW" HEADSHAVERS STAY AWAY FROM "NAIR"!!!!  it is NOT intended 4 the dome.  it will irritate & cause rashes.  i've learned that from other headshavers who have tried this product.  again... stay away from "nair" & get a quality razor 2 keep the noggin' slick.
WARHAWK 
 
						
MEMO:  2 ALL  "NEW" HEADSHAVERS STAY AWAY FROM "NAIR"!!!!  it is NOT intended 4 the dome.  it will irritate & cause rashes.  i've learned that from other headshavers who have tried this product.  again... stay away from "nair" & get a quality razor 2 keep the noggin' slick.
WARHAWK 
Click on the link below and scroll down the page a bit to see what  can happen when you use Nair on your head:
http://household-tips.thefuntimesguide.com/2007/02/tips_for_shaving_head_bald.php
						
I don't think they'll do electrolysis on such a large area as the back.  Don't the hairs have to be removed one by one with a needle?  It would take forever.  Also sounds painful.
Yeah it would take a long time, need to be patient.  But electrolysis does not hurt much (hurts a bit less than tweezing...is that painful?)  if your practitioner is skilled.  That's why it's important to search for people who have lots of experience and know what they are doing.   Laser can get you permanent hair reduction but usually no permanent hair removal.  My practitioner did laser on her son's back and the hair grew back.   She told me she will do electrolysis on his back soon.  She does the back of my neck because below the natural hairline I shouldn't have dark hairs but I do.   It doesn't hurt much because she is skilled.  But man if the practitioner is not skilled may God help you with the sessions.   A different lady was doing my first 3 sessions, and she wasn't that good at it, and I can tell you it hurt a lot.  
						
I dont think I have back hair but I do get very thin hairs on my shoulders...I just shave em every few weeks...doesnt really bother me or my wife.  I cant imagine shaving it with a trimmer could cause THAT much irritation... 
						
                        
					
		
					
					Maybe I'm atypical but I fail to see why guys freak out over back hair. I just let it be.
Now my ear-lobe hair, that's gotta go!
Any ear hair at all...I tweeze my inner ear hair and a few strands here and there every few days. I have a few patches of back hair, but I also have leg and chest hair. I am a guy. I have been known to keep the body hair trimmed up, but I don't know why a guy would want to be hairless all over. Shaving my face and head is one thing, but I'm not shaving anything else. Legs? Back? Not for me.
						
ear hair gets tweezed here once a week; periodically i wax the back.
						
                        
					
				
					
					I've got a hairy back and chest, but said "To heck with it".  It's how I was made.
I am the Austin Powers type of hairy on my chest and my back is pretty hairy too.  I have trimmed it in the past, but I'm with Pruitt, to heck with it, it's how I was made.  The contrast of the shaved dome with the hairy body is a manly look.
						
I got the Austin Powers thing going on on both my chest and back, arms, legs, etc.  only times 5.  I don't really care if others like it or not because to shave, wax, or etc. would be costly and ultimately not worth it in my opinion.  However, to those who chose to do so, more power to you!  I kinda wish I wasn't so hairy but that's life.
						
                        
					
				
					
					My woman shaves my back periodically with a hair trimmer
						
                        
					
				
					
					
					Hairy backed SLY guy here too. I do let my wife trim it down several times a year though she tried waxing me once. I won't EVER do that again!!  OUCCCCCCCCCCCCHHH. Only time it truly bothers me is summer since it causes alot of discomfort. I don't mind the hair on my chest but the back hair can be a nuisance.
						
                        
					
				
					
					Cheapest and what I find most effective as a summer volleyball player- Get a dark enough tan where it's pretty unnoticeable...