Did this. Those spray heads are often G1/2 British Standard Pipe (BSP) so I used a fitting like this which took it to 1/2" npt then a garden hose fitting on that.
Hey I went with this element from Brew Hardware, and this inexpensive controller idea from StillDragon. It's all wired through a spa panel gfci for safety, cheap and works a treat!
Ok I'll let ya know, I use the same bag material, only small size, loose in the kettle for my hops and they are all over the element during the boil so think it'll be ok, hopefully!!
I have the exact same set up as you, here's what I've been doing. Mash in, my kettle sits on a large folded up beach towel to reduce losses out the bottom, put lid on, wrap entire kettle with sleeping bag. It'll sit at mash temp for 1/2 hour and drop 1 or maybe 2 degrees, then remove sleeping...
I'm using less water, my evaporative rate is around 1/2 gallon/hour, still dialing that in. Certainly has a strong smell but was able to reduce it by draining into a sealed stand pipe I built for my floor drain while brewing.