I do Second to None's groc store shops, but I always wait until they bonus well. The work required is just not worth it until then. I have found them rather awkward too. Hanging out waiting for someone to approach you... then coming back a second time to each department to get someone to approach you... and then making up what to ask them... awkward!
In my area, the grocery stores often have a grill/bar attached, so you can grab the store and the grill/bar shop. When they both bonus enough, I jump right in.
I've grown rather fond of having a bloody mary or two in the bar and then doing a grocery shop.
Just out shopping around...