I use poly-nylon 1" mule tape,Alot & It is some tough stuff,knots have no ill effects on mine,however cinched figure-8's & bloodknots for example,Will require needle-nose pliers or a marlin spike to undo,so be mindful of such.I use a fishtape for pulling wire myself,never heard of muletape doing the same,it's not stiff enough to feed,though it could be shot with co2 on ug conduit I suppose!