Nothing says 'half-arsed maintenance' like GT85.
Brake cleaner is more or less a waste of money – contaminated pads should be binned and contaminated rotors can be cleaned with hot soapy water. No need for "specialist" cleaners. Although isopropyl alcohol can be used and has other uses in the workshop/home, it's by no means a necessity.
You'd have been better off getting some 3-in-1 silicone lube which you can use to maintain brake calipers. It'll lift dirt off, lubricate the pistons/seals and, with the excess dried off, will leave a low friction coating on the caliper which will help to prevent build-up of dirt and brake dust.