You are talking about Megs Wheel Brightner I assume? Yes, its a great product and it can be cute down 4:1 so you get 4 gals out of one bottle. And compared to Hot Rims, its a lot stronger and needs less to work with. I can usually use maybe 8 oz on a car and thats kinda on the high side. Its super strong stuff and you should use PPE with it. And make sure your wheels don't have any curb rash on them or else it will get underneath the coating and cause a lot of damage.
For the price and compared to Hot Wheels price point, there really is no comparrison. Hot Wheels is too expensive for my tastes and like you said, you use a lot and its not cost effective.
Also might wanna look into some Iron X for really bad wheels. I'll use it after I knock off the majority of grim with the WB then use a SwissX brush and spray it with some Iron X and work it over the grime that the WB didn't get out. Works wonders on BMW wheels.