This worries me. I've always thought of Star San as a contact sanitizer, so spraying on the surface and letting it sit for a minute or so seems like good practice. Can you elaborate? Do you feel that some agitation is needed?
First off, You cannot sanitize something unless it's clean. So we need to make sure that criterion has been met.
Sure, Starsan is a contact sanitizer, but it needs to contact for 30 seconds to 1 minute. If it beads up and drips down the sides there may not be enough contact time, and certain areas could remain unsanitized while (small) scratches may not get wet enough all the way through.
I immerse most of my smaller equipment in Starsan, including (mason) jars I collect and store ranched and harvested yeast in, starter flasks, stoppers, airlocks, hoses, etc. Actually, racking hoses remain submerged in a bucket of Starsan, they never get dry. They turn milky-opaque, no big deal.
Glass carboys get a gallon and I shake them up a few times to wet thoroughly, then drain. Buckets get 1-2 gallons and get "mopped." Rims, lids, grommets, spigots, and other bug traps get special attention. Agitation helps, sure.
In all those years I've had one starter from reclaimed yeast get unintentionally infected with Lacto. Used it to my advantage, and increased it to become a small batch.