good idea, but still why the need to add string, if just rubber bands are used instead of string, wont they pull much harder,
as for clit torture, i want you to do something similar. you will need about 20 rubber bands and about 6 to 10 clamps.
now clamp your clit with equal number of clamps both side, do remember to rubber band the clamps griping side so that they wont get pulled off your clits easily.
now connect left side clit clamps to left side foot thumb using rubber bands and right side clit clamps to right side foot thumb, this way your clit will always be pulled and stretched,
the fun part is you can wear cloths on the set up ( loose clothes so it can hide easily) and no body will know that you are being a slut with non stop clit stretching.
as rubber band will shrink and stretch as you move your legs.