I agree that this would be against the rules of golf.
I played a guy back in AZ who was legally blind - and he found that tying a string to his tee really helped him pick his line and path to swing the club. But he said he could no longer play in tournament events - because without the string - he couldn't easily decipher where he needed to aim/swing. Kinda sad too because the guy as a Sr. golfer was pretty good.
This thread made me think back to this gentlemen, and I believe it would be viewed as an alignment aid which is against the rules.