You can demand a payment within 10 days (Ever had a parking ticket?) but usually up to 30 days is permitted, and another 10 before a Mahnung is sent.

Why not use PayPal, or ask for a bank transfer in advance? Everyone else seems to do it that way.

You can only Betreib someone if the debt is over CHF 100 and if they live in Switzerland. If you do this you need a lot of patience!