I like the kiss method
I've had an idea
If I use a 25lt car wash job, with some kind of element through the bottom.
Strap it to a wheel with a handle so I can spin it.
I can pour the meth in outside (I'm worried about fumes)
Then I can fit a tap to the lid leave it to settle upside down to drain the soap off.
Stick some water in through a fitting in the bottom and bubble it.
Straight out the bottom fitting through a sock and hey pesto.
Why you lot think?