100% pure silicone spray has worked well for me to clean and lubricate rubber seals, as on slides and the rubber seals around doors in vehicles. I get a clean rag and spray the rag until damp and then wipe the seal. It cleans it and lubes it in one operation.
There's lots of advice and information in forums... sometimes it is correct. For example, all of my posts are made by a political appointee who got the job as a reward for contributions to my diesel bill.
2011 Jayco 28.5RLS; 2008 Chevy Duramax; Pullrite Superglide Hitch