The Maiwa vat is very simple and works.
This is a mohair boucle and it is lovely. I dipped half the skein and draped it over the edge of the pail, took it out and let it change to blue, then put the whole skein in for a short time.
And I dyed cloth, one edge in each vat and move it back and forth. This is a length of cotton from the Grandmothers to Grandmothers sale. Think it's cotton might be a blend but indigo is very cooperative and seems to dye everthing
This piece of fibre (again, probably but not provably cotton) dyed with found rusty objects then overdyed with Indigo