LR Classic CC: Marking comments read

I must have missed something – how do I clear the yellow comment icon for new comments for multiple photos at the same time?

I know I can browse to a photo and leave it there for a few seconds before moving on to the next one, but that's not a good workflow when you have tens and hundreds of photos to mark.

When sending photos via Shared Public Collection and getting the client to hit likes for chosen photos I can reorder by Last Comment Time and that's great to select them all at once, but that red indicator for new comments doesn't go of like that – instead, that yellow mark stays there unless I go selected every one of those photos one-by-one and stay for a couple of seconds.

So, how do I mark several selected photos as no-new-comments to them all?

Thanks!

I haven't used the commenting feature much as it requires the client to register an Adobe ID account so it's too many steps, but, I've now made myself a second Adobe ID that I give to clients to login so it's a bit easier for them.