I have been cleaning my brake calipers and wanted to flush them in case I got any dirt or water in where the brake line attaches or in the piston locations. I am sure I can use brake cleaner to clean out the piston holes. I was thinking of setting up a gravity flow process where I could place a funnel at the screw hole where the brake lines attach (see arrow in pic) and then let some fluid drain through. So, is there anything instead of brake fluid, i.e. mineral spirits or kerosene that I can use to flush out the inside of any debris or water before I put the bleeder screws back in and that won’t damage anything inside the calipers?