I heard that alkali cooking 40 years ago, but first time I cooked them last summer. It was really usefull work.
We all have in Finland small houses sauna and in most sauna we have a big pot for warm water and fire place under the pot. I have some 80 liter.
method:
Put old dirty frames in 10 frame bunches or proper.
Warm water in big container , barrel half or something to near boiling temperature. Make 3% alkali liquid. Also you can use crystal carbonate (for painters).
When water is hot, it loosens all wax and dirty from frames. Alkali transforms wax to soap. It catches any more to frames. Bee excrements get rid very quickly.
After that I diluted frames in water to get rid of alkali.
It was quite easy work, and you can handle in one hour about 100 frames. They are like new ones. It is a good sum of pure money.
In Denmark they keep old wires in frames and cook them too. You just only tingten the wires and you save work.
I have read about it but saw it was not recomended for a beginner, so I guess if you are a few years into bee keeping it would be something to look at. bye
I have a 15 gallon grease drum that I welded some legs on. I build a wood fire under it to heat the water. I use Arm & Hammer washing soda (sodium carbonate) and water. Does a nice job cleaning frames.