There are simple cleaning instructions inside the box, it is extremely easy as both ends open up. You can clean the inside glass cylinder with east and the infusion chamber comes apart for ease of cleaning as well.
It depends on the use, if you use them for whisky and char them with heat then they will be whisky flavored forever if you use them in a rum or vodka you can reuse several times before getting new ones.
Don't see the answer to your question? Ask the project creator directly.