You might get some answers if you provide a lot more explanation.

I believe polyHEMA is used to make low attachment plates. If you search polyHEMA and low attachment plates(something similar) on google or researchgate, you will surely find a lot of search results. Here is one of the pages from researchgate regarding this: https://www.researchgate.net/post/Preparation_of_spheroids_with_PolyHEMA . Here is a paper which gives protocol-http://www.nature.com/nprot/journal/v8/n7/full/nprot.2013.076.html . I tried making the plates but i forgot to turn off the air inside the hood. So the ethanol evaporated and polyHEMA solidified too quickly; only spreading to some parts of the well.  You have to either turn off the air in the culture hood or find another place(i think it has to be sterile) where the ethanol can evaporate more slowly. You have to make sure that it is evenly spread out and covers the whole well. But I can't tell you how well these plates work as I haven't really used these plates. We actually buy the commercial ultra low attachment plates from Corning and don't use this method. But i am sure there are a lot of other people who have used this method and can help you out.

I know this is a reagent to transform tissue-treated cultureware to low-adherent plates. https://www.stemcell.com/products/aggrewell-rinsing-solution.html Catalog #07010. I bet this will be cheaper than buying ultra-low plates alone.