Do you add the hops to the keg without any bags
I got my Flot-it on Amazon. It does indeed come from the USA. Hops into the keg after keg purged (quickly open the keg and chuck in). I purge my kegs with CO2 from fermentation, so can't put the hops in prior to the purge. Transfer beer on top (no bag).
I can't say I've noticed a massive difference Vs using a big nylon hop bag, but it's a pretty cool system.
Like I say, I've read of people using cask widges in the same way.
https://caskwidge.com/Parts/Product/17