cleaning & re-sealing

I would not use soap on your unit. I would use a detergent. Something like Simple Green is an excellent cleaner for the coach.

Everyone has their favorite. Dicor lists about 30 that are considered safe for EPDM and TPO. The important thing to remember is not to use anything with citric acid or petroleum distillates. I like Murphys Oil Soap.
A medium stiff brush works fine but do not get too agressive on EPDM. With TPO, scrubb all you want.
The roofing material itself needs no sealer. For seams I like Dicor 501. On verticle surfaces Dicor 551. Many use Dicor or Eternabond tapes.

Simple green, dish soap, any mild detergent with a good soft truck wash brush on an extension handle works well. If your rig is extremely dirty with black streaks, have a spray bottle with concentrated detergent ready to hit those spots.

I use Duragloss 901. It cleans very well and rinses clean. As for the rest of the RV I have tried many things over the years and have found Duragloss sealants to be the best. Last year I did a buffing routine with an orbital and wool pad using 652 to help clean up oxidation and years of yellowing using carnuba products. Did 2 coats of 601/105 which was on there for 14 months when I decided to recoat before the dreaded oxidation set in again. This time I did 601/501 first then 601/105 on top of that. The 601/501 removed any minor oxidation and cleaned the fiberglass for the final 601/105. The 601 makes the sealant set up like epoxy which then helps with the longevity. During the year the RV will get maintenance washes with 901 and dried using Aqua Wax or rinseless washes with 931.

Dave