well i have done plenty of nat. crotching but never false crotching. i under stand the basics of it, block/pulley on whoppie sling then notch, then half hitch then running bowline. so my question is what not do you use on the sling holding the block and the porta-wrap?, and dose anyone know where there is video or any website that gose in to detail on the whole rigging?? thanks for your help and advice.