Audio control accessibility mechanisms

Hi all, apologies if something like this has been discussed, but I couldn't
find it in a search of the archive.

My organization has a large number of auto-playing videos on its pages, and
no easy mechanism to mute them. This seems to violate the audio control
rule (1.4.2), so I've been looking for the best mechanism to rectify that.

The ideal solution would be to play videos muted until the user unmutes
them, but I'm not sure that will fly. The suggested technique on the WCAG
page is to have a control near the beginning of the page that mutes all
audio (which is an avenue I could pursue), but the other option I was
considering is to just have the space bar pause the video, the same way
YouTube does. This wouldn't be spelled out on the page, so I guess the
question is whether the "space bar pause" has entered the web interaction
lexicon enough that users just know to do it. If that's the case, then
maybe the space bar pause is easier than tabbing through the page to find a
"mute all" button while a video is playing.

Is the space bar pause a satisfactory resolution to this problem? Am I
missing an obvious problem with it? Or is there a better option that people
are already using that I just don't know about?

Thanks,
Eric