Xapo have a internal ledger system, keeping track of internal transfers between Xapo accounts and none of this is reflected on the Bitcoin Blockchain. So no miners fees are payable to the miners, because these transactions are off-chain. < So doing transactions between Xapo accounts should be free >
If the faucet owner has a Xapo account and you have a Xapo account, these micro
So yes, you made the best decision to use Xapo for micro transactions < also called Dust > ^smile^
https://support.xapo.com/is-there-a-fee-to-transfer-between-different-currencies-within-xapo/view=faq
Make sure that you adhere to their rules, https://xapo.com/terms/