I pulled vacuum for 3 hours and then cooked the blanks. I did not seem to get any penetration. What is going on here?

Penetration issues are almost always caused by not letting your blanks soak!  Remember, while you are pulling vacuum, you are pulling air from the wood and very little Cactus Juice is going in.  The vast majority of the resin uptake occurs AFTER you release the vacuum and it does not happen right away.  My rule of thumb now, after years of experience, is to let my blanks soak for at least twice as long as I had them under vacuum.  In other words, if you pulled vacuum for 2 hours until the bubbles stopped, open the valve and release the vacuum.  Then let them soak at atmospheric pressure for 4 hours at least.  Longer will not hurt the Juice or the blanks in any way. I frequently leave them soaking overnight.