Well what did you imagine that ringing bells and "meditating in Sanskrit" rather than English had to do with physical exercise, if you insist that this part of it wasn't woo silliness?
I - and all of the other participants I spoke with about this* - looked at it in this way:
Firstly, it's relevant to know that in the (relatively) exertive forms of yoga that I practise, the last 5 mins of a typical 1-hour class are spent in a motionless relaxation posture. And - in an entirely non-spiritual way, I (and most others) find I can gain some real meditative benefit in those 5 minutes.
Some teachers spend the last minute or so of the 5 saying general meditative things like "Take this time to centre your mind and your body" or "Feel ready to awaken your senses again and face the day ahead with renewed passion". Now... some of this sort of stuff definitely comes close to the line into "New-age psychobabble", but I really don't mind it.
So on the extremely rare occasion that one teacher chose to do some Sanskrit chanting and bell ringing, it was unusual for sure. But it happened in that last minute or two of the relaxation period at the end of the class. We all treated it as nothing more than part of the relaxation/meditation process (much as, for example, some people who would in no way consider themselves religious Christians might feel calm if they listened to Gregorian Chant).
I have no idea as to the motivation and intent of the teacher in doing that, but as a "recipient", it didn't feel in any way like I was being in any way proselytised. It was pleasant, soothing and relaxing - that's as far as my feelings about it went/go.
* because, as I stated in my post, this was an extreme outlier so it was a topic of conversation for people after the class had ended