is it an actual rubber band or is it those ones that are just like stretchy...idk...like threads that are stretchy and dyed different colors? if its just a regular rubber band, i use those all the time for gsp, (actually i've had one in there for like 4 months cuz the gsp overgrew it), no problems...but if its the ones that are dyed, i'd be warry of using those...the paint or dye or whatever could leach, could it not?