Probably obvious but, The trick to oil pan leak repairs using sealant is 1) clean ,2) heat (to draw out any oils and contaminates) 3 repeat until spotless. . 4) scuff up the area 5) cover an area at least twice as large as the suspected leak don't put into service for at least 24 hours
I have seen multitudes of leaking bad repairs and repaired many rusted pans I am not a fan of silicone as a external patch. (Ford's were notorious for big potato chip sized rust spots appearing out of nowhere)
I like JB weld. A heat gun will remove any air from the Jb weld and help it smooth out as a last step.
(My FAV) 3M 2 part panel structural adhesive that works great as a surface patch. Pretty $$$ thou. This had become my go to method. Process is same as JB , do not use in very high heat areas
Have used 3M on rusted metal, aluminum cracks (housings) , rub throughs , all on long standing customer cars (with their approval of course to save $) and never really had a failure after many years. Kind of makes us giggle when we see your Gerry rigged patch job last for that long.
Jerry Sr