You have the right idea using the rockwool macro-plugs but you are making several errors:
1. Soak plugs in 25 - 50% strength nutrient solution overnight and this is what you will use to water the clones as well (pH adust solution after soaking).
2. DO NOT SQUEEZE the macro-plugs. Doing so destroys the rockwool structure that is required to maintain the optimum air/water ratio for which rockwool is justifiably famous. When you pull them out of the nutrient solution, you can shake off a little water if you like...or not.
3. Get the Grodan Gro-Smart tray insert. That tray insert you are using DOES NOT provide optimum air circulation for rockwool. Alternately, set them directly in a 10" x 20" nursery flat. (A big advantage of the Grodan insert is that you can lift it out of the nursery flat and easily see which plants have roots. Wait for at least a dozen roots to emerge before transplanting.)
4. Cut the clone stem at a 45 degree angle and immediately insert into the macro-plug. You do not need to goop them, that only encourages rot.
5. Use a slightly ventilated humidity dome.
6. Wait 7-14 days and make sure the rockwool does not dry out entirely. Use a turkey baster to squirt the aforementioned pH adjusted nutrient solution on them as needed.
7. Some strains yellow out severely during this process and some do not. Keep mitts off until well-rooted.
NOTE: To all the people using anything other than rockwool plugs, you are missing the boat. Rockwool can be easily transplanted into anything, transplant shock is not a concern. You can't over-water it, excess water drains off. It doesn't fall apart like, say, sand. It is inorganic so it doesn't rot. The only prep required is an overnight soak to balance the pH.