Something that involves 45 minutes of your time every day for three weeks, every six months... I don’t know if I would describe that as “the best avenue”. It’s not as if it’s something I can do while sat as my desk at work.
You need more accommodating coworkers. If you can't take your testicles out and dip them into nearly-scalding water at your desk in the open-plan office, you need to do some trust falls at the next morale event.
"How dare you disrespect my reproductive autonomy!"
So what you're saying is that there's a market for devices that would let you do it while sat at your desk at work?
you can work with an oculus go or quest and voice control if you keep your head above the water
If that's the only reason you're taking a bath, then sure. If you enjoy a good soak every now and then anyway, though, it can be a nice side effect (or an unwanted one, depending on your goals).
I think a 116F tub is above what most anyone could tolerate for 45 minutes.