The primary cause of oring problems is over tightening the sump, and attempting to remove the sump without all the water pressure being relieved first but... if the oring goes on the outside of the sump, that is a very poor design. Real BB(lue) filters the oring goes in a groove on the flat top of the sump. The bad type is Omni IIRC. Real BBs are blue made by Ametek/Plymouth Products/Pentair now.
Vegetable oils can cause bacteria problems and may cause damage to plastic parts; as petroleum based products do. Lubricants are not a sealant, so a light thin coating only of silicone so the two parts can slide on the oring without sticking which will stretch and deform the oring.
Gary Slusser
22 yrs in water treatment and well pumps, 13 yrs helping people on the 'net to help themselves.
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