It does what it sets out to do, cleanse your beauty blender and brushes. However, as a fan of deeply cleaning using liquids I just can not get on board with this solid version. It comes in a tin that keeps it in a nice state but when using you swirl the product into the balmy cleanser and end up with it all becoming a bit messy with it being used up in only a dozen washes as the water erodes at the cleansing bar.
It is effective and gets everything clean, and if you have a BB or 2, and maybe half a dozen brushes then this could be a good method for you as it is fast and you will probably get a few washes out of it, but as someone with a lot of BB and brushes it just isn't economical or effective enough and that is the reason I stick with the liquid versions. A little gimmicky for my liking.
I got a few minis of this in the Christmas Beauty Blender sets I bought last year. This is some concentrated stuff. Now if you think you just roll your wet BB in it and with a little lathering in your hands all the staining comes out that's not how it goes especially if you wear a long wearing foundation or you're a deeper skintone so your foundation is darker. I'm a Mac NC25 my foundation doesn't immediately come out.
I do have to really lather it up and rub it a few times to get the foundation out, but I have found this solid gets out the stains much easier than regular brush cleaner and even a bit easier than the liquid Beauty Blender Cleanser. If I have washed my BB and I have some staining left on the sponge and it's dried on and I use it again and use the BB solid and lots of effort it can get out the old stains leftover from the previous wash. I can't comment on how this works for brushes because this is pricey I save this for my BB, but based on how my BB liquid cleanser cleaned my brushes in the past this would easily remove any makeup out of my brushes. I would recommend this for anyone who wears long wearing foundation or really doesn't like stains on their BB.
Tips: This stuff is really concentrated so you really need to rinse it out well. I don't have the full size so I store mine in soap dish so it can dry in between uses. Now this stuff is spensy so don't run it under water instead wet your BB and rub the wet BB over the soap where you have stains and foundation. Your BB will not be as bright hot pink after a few times of using this to clean it because it gets out the dye out of it as well, but personally I don't mind.