Odd that I thought I previously posted a link to at least one product you can use to accomplish this by outputting a clean copy of the files outside of Plex but then Plex can be used to play them.
Here is the information:
This solution is not super easy to setup/configure but it works great to accomplish having content filtered for any language or words you wish to be removed.
Cleanvid:
Python script to parse SRT files and re-encode video using ffmpeg or output an EDL file.
You will need Python and ffmpeg installed for it to work.
Can also be ran in Docker.
Usage:
cleanvid [-h] [-s ] -i [-o ]
[–plex-auto-skip-json ]
[–plex-auto-skip-id ]
[–subs-output ] [-w ]
[-l ] [-p ] [-e] [-f] [–subs-only] [–offline]
[–edl] [–json] [-r] [-b] [-v VPARAMS] [-a APARAMS] [-d]
Examples:
cleanvid -i testvideo.mp4
cleanvid -s testvideo.srt -i testvideo.mp4
I also found using the -f flag lets you keep all of the closed-captioning for words outside of filtering in the event you want it on or are watching it muted.