I'm working on a rocket belt.
The main barriers you sorta run into with this technology is finding spare parts for the tanks and a source of peroxide.
I sorta fixed both: the fuel tank they used on the original one by bell is a D-2 oxygen cylinder repainted, they're 5k new and 200$ on eBay.
The peroxide problem I sorta solved from two approaches, you get a concentrator for solvent extraction (rottavap) and buy the 50% stuff.
The second one is you can burn a fuel like a hydrocarbon in an "afterburner" but it takes a sparkplug under 70% since the vaporization enthralpy on the water is eating your temp to under 200C