definently wouldnt bother with the "issue"

if thats his hunting style, thats his hunting style. PUT him in the best spots...to see game. places he will be happy to hunt.

then...find yourself a big buck sanctuary...if grandpap is in there stinkin up the place, they will just avoid him and his stand...

or, help grandpa hang his stand...but put it where the typical dominant wind WONT hurt anything...i know in western PA i can generally expect a west wind..generally..keep the thicket and food sources anywhere but in the east of the stand and you aughta be ok on typical days...maybe not perfect...but its an option thats better than nothing...

or, take grandpas clothes home and wash them...and when he aint lookin once in a while spray him with scent killer