You put a drop on the end and hold it on rim of eye. It works great and saves on drops

How is it applied? Do you actually touch the eye or just the lower lid?

The applicator never touches. Only touch the drop to your lower lid. If you have any furthers questions you can call Nikki or Mike O. @ 941-727-3444.

How long will an applicator hold its tension pattern

I'm not really sure I understand your question. If you're asking how long the drop stays intact on the applicator, the drop will stay on the applicator until you bring the drop to your eye, or touch it. Once the drop is on the applicator, you can actually turn the applicator 360 degrees, albeit slowly, and it will remain on the applicator. (I never do that, but after reading your question, I tested it.) The tension does seem better on a dry applicator, so I do sometimes turn the applicator upside down between drops so I can use a dry side for each eye.

Does product need cleaning when using more than one type of drop at a time?

I can't answer 100% but think it would most likely be wise to rinse if ott with some hot water and blot dry with maybe a tissue between each eye and each drop. I only use one type of drop and I hold it under hot water for a quick rinse and blot it dry between using for each eye.