I actually am thinking about making something like this as part of an OpenBazaar integration.
However, outside of OB, this is a laughably stupid concept for any crypto. In Dash all you need to do is "check" a wallet in the GUI to anonymize your payment. For other cryptos use Shapeshift or an Exchange. Stuff like this is just sketchy. Why would anyone want this...
This website is not decentralized, btw.
"To be precise, we purge your order from our database after the bitcoin payment we make on your behalf has 144 confirmations (about 1 day). After 2 more days, your order will be purged from our backups. That means all records of your payment will be gone from our system after 3 days."