I don't mean to be fussy, but you do realize that by spraying your tree straps, you are killing every little critter that goes up and down the tree trunks, even if they would never detour to get on your hammock.
I spray or soak my hammock for the mosquitoes, but my tree straps? No. But, ... of course hike your own hike.
I'll take that under advisement and see what happens without spraying the tree straps.
Keep movin', keep believing and enjoy the journey!