Yes worked for me but all jobs are different. Good luck with it. Let me know how it turns outWill give it a try. Worked, you say on difficult water stains/etching?
I use dawn and white vinegar
It has been incredible amazing
Soap Scum Remover: 1 part Dawn to 1 part Vinegar
If you have soap scum in your tub or shower, this duo is your new best friend. Add equal parts Dawn and vinegar to a spray bottle and shake gently to mix. If you have really tough deposits, you can heat the vinegar in the microwave before mixing for a little extra power. Spray all over the tub/shower and let it sit for a few minutes to a few hours, depending how yucky the target. Since the spray is thicker, it clings to the walls and shower doors rather than running right down. After it sits, scrub if you need to, but you’ll probably just be able to spray it off and have sparkly surfaces. It’s a little stinky while it sits, but I much preferred the vinegar smell to the nasty chemical smell of Scrubbing Bubbles, and this worked a ton better! Once you rinse, the leftover smell is more like Dawn than the vinegar.
Someone else mentioned that Magic Al Glass and Metal Magic. It is on order now. Will report back on how it works on nasty glass shower doors. Will try stone scrub again with my op.Ya need abrasion/acid for that stage of hard water stain.. i know you dont want to use acid but personally i dont like wasting time, just dont atomize it and use cold water. Gel version good option if ya get it 27% acid. Get one that safe on porcelain and chrome as well.. Of course i dont use it on natural stone situation...
magic al is great. its like soft scrub but way better. works really well when Mikey let me tried it.
I use razor, orbital or makita and red pad or white pad with stone scrub and go to town. I have been very successful doing that and quickly. Its my favorite method. Situation with stage 3 issues, ya need more power than plain elbow grease..