I usually use my non-playing index finger to apply the lotion to the crosses, although it does not take very much lotion. I just put a small dab on my index finger and do one side of the crosses, then one more dab and flip the racquet over and do the other side of the crosses, then move the mains back and forth. If I forget and put it on my playing hand's index finger, I have a towel in my bag that I thoroughly rub it off with.
Same here...piece of cake. I dont even move the mains manually. I just do a small dab on the string bed, quickly spread it around, then swing away. The first ball that is hit after relubing feels very very obviously different.