Of all the cleaners I used on my '05 Suites, most worked for a short time, but none was really effective. All kinds of advertising claims/endorsements, but the system is basically faulty in that the sensors stick out in the tank and collect crud. Suggest you look into the SeeLevel system to solve this problem.
2016 Tiffin 40 QBH
2015 38RSSA, traded
2005 TK3 #1869, 10 yrs of memories,
2017 F450 KR--one more Ford is it
2009 F450 4x4-died; 2010 F450-retired