The Dicor Self Leveling Sealant is great for roof seams/around vents etc.
But doesn't work very well on vertical/sidewall needs.
Dicor makes a non-sag sealant
Silicone should NOT be used.........silicone leaves behind an all but permanent coating to which no sealant, including fresh silicone, will adhere. If a silicone has been used it must be completely removed using a silicone remover.
For vertical/sidewall sealant I use ProFlex Flexible RV Sealant by Geocel Corp. NOT FOR USE ON RUBBER
Pretty sure CW sells it.