A more risky approach, if you can’t find local people to supply you with unicycles, would be to buy some and then resell them afterward. But this would only be a good idea if you can’t get anyone to bring theirs…
This is a great opportunity to start a unicycle club in your area.
Our club has about 20 unicycles that we let new-comers use at gatherings and when we do workshops and uni camps as you’ve described. Also, to help underwrite the costs, we rent the club unicycles for $10 per week. This works out for everybody.
Just to clarify: I read this post and replied to it in the Requests forum. It was there with the addition "Moved: " to the subject. I thought it was moved TO the Requests forum. But I now think it was moved FROM the Requests forum to RSU. Sorry for the off-topic ramble.