I'd thought about gauze, but it seems pretty insubstantial. It doesn't seem like it would absorb much solution. What's needed is something like absorbent cotton in a ropy kind of format. Is there any such thing? I don't know. Tree nurseries use burlap that comes in strip form to wrap the trunks of young trees. It's probably pretty cheap and available in long rolls. I wonder how that would work?

EDIT: Just checked a nursery supplier--they sell 100-yard rolls of 4-inch burlap for about $9. That sounds pretty promising.