Here are a few tips I have developed over the years. Start by sealing off the fluid reservoir with kitchen plastic wrap(cap applied over wrap). This keeps most of the fluid from leaking out when brake lines are removed from calipar, at least slows it down. When old calipar is removed. I then stick a Q-tip in the line/s to further stop the fluid. I use the ones with a wooden stick with stick cut off one inch from the cotton tip. I use a EZ-Bleed presurized system to bleed the breakes. While bleeding a new calipar, I constantly tap the calipar with a hammer to get the air bubbles on the inside of the calipar to release. Just did a calipar replacement. on my '88 244. It took many cycles while tapping to get all the air out that one calipar.

Hope this helps.

Gary in Maine