For everything to be non-custodial, you should avoid using sideswap and use a different atomic swap provider (different from the one used in the first hop), since sideswap requires trust in the pegout.

This software would be fantastic. You put in one bitcoin and, for a fee of less than 0.5% to make it profitable for everyone, you get another clean bitcoin. To make it even cheaper, the software provider could offer the first atomic swap jump, so that they would keep the profits.

The business could be profitable by charging just 0.2% for anonymization.