Are you talking about the a/c condensation drains? If so, in other brands RVs I have owned you could blow the drain lines out with low pressure water or air. "Low" to my mind is 15-20 psi, enough to push water & debris out without jetting it into the a/c unit or bursting a line if it is badly plugged.
I've not had luck with pushing water up.... I can get to mine via a ladder w/o getting on the roof. I have a 17ft Little Giant Multi Position Ladder which is a tool I use often around the RV and use the step ladder function to reach the drains. I take a cloth, wrap it around a pistol grip water nozzle and try to direct a jet of water down the drain. I get wet but it typically works.
Have a friend with a 2017 Dutch Star and he's glad he removed the screening and keeps it off. Easy to clean then but I haven't gone that far.
I also hate RV sites with overhanging trees which just end up polluting the roof and drains.