Cable-tie a Tyvek or laminated note to the main belay points (or the bottom of the rope if upwards) explaining the situation and ask that folks treat them nicely if they use them? Then if folks do decide to use them instead of their own, they may take more care than usual.
I've got some upward ropes rigged for a dig where I've had to leave a note asking folks not to use them unless they contact us first, as it's an area that's not been rigged before, it's sketchy, it's definitely not friendly or necessarily kosher rigging in places, and I'd rather they didn't risk it without some additional info. Obviously they still could use it without asking, but my conscience is clean if it goes haywire afterwards. Once the project is complete, we can then decide if permanent rigging is suitable there, and a topo provided. It's a tricky one when you're doing upward explorations, as by definition, you have to leave the ropes in place until you're done, if pull-throughs aren't practical, which they rarely are. I've got quite a few dangling down from holes around and about now.