well, I be in serious bigtime trubbles..... because for the last 20 years or so:
I buy the $0.99 2.5 or 3 inch wide disposable paint brushes at Home Depot.
the same "brand" ones you see in BB&B as "pastry brushes" for $2.99 each.
they get used for lye; they get used for water / butter / oil on strudel / puff dough / filo / salmon / trout / etc / etc / etc.
they get a good rinse - hot or cold depending on butter/aqueous brushee - and go thru the dishwasher.
I can understand the silicon brush thingies would be seriously unsatisfactory. somebody gave me one for Xmas one year - I think I tried it twice before it chucked it....