Well, without CV curves I still ended up doing them as if they were real shoelaces. Although at some points it was annoying as some facets kept going through each other at every twist.I would think this could be done using CV curves. But I think you would need to do it like you were actually tying some real world shoelaces.
I'll try to delete the history next time, maybe that will work on that character i've modeled too (though it had way more changes than the shoe and it still didn't lag more than 2 seconds at most). Thanks.It might be the history... it builds up over time, so if you delete that, it shouldn't lag so much.