Gel Prep vs. betadine scrub and solution

Hi just wanted your opinion. I was wondering is it universal that all total joint procedures have a 10 minute prep? And how long should the betadine or whatever solution you are using stay on to make the prep effective? We have had quite a few discussions regarding the prep which brings me to the 3rd question. Have you used gel preps and what is your opinion on them? I would appreciate any answer. Thanks Cammie