Careful with Houdini Swap. Maybe they're legit, but you have to trust them since they know both sides of the swap.

Monero Talk podcast did an interview with them about a year ago explaining how it works and other details if you guys are curious:

https://www.youtube.com/watch?v=7-8dOdFybOs&t=3182s

If you want to turn up the paranoia dial better to do Swap#1 on 'Exchange A' and do Swap#2 on 'Exchange B'

1. Let some time pass before you do Swap#2. Maybe a day or two. The more time the better. (resists timing analysis)

2. Don't swap it all back in one shot, break it up into a couple chunks (resists amount analysis)

3. Get behind Tor or at least a good VPN. Change Tor identity or VPN server for each swap.