How abt a terracotta tumbler?

Sir, i have tried making a terracotta tumbler which has a plastic lid exactly like a simple plastic tumbler. i have made the product with paper pulp for the time beinng now i need to test its airtightedness. i cud not send the pic today due to sum prblm in camera. but i hv tested the action of a ring in the contatiner to help churning and it works.the tumbler can be used setting curd and then also preparind lassi.