yes, repair is not a valid option to see all available option use DISM /? if you need more help with an option just add a /? after it for example DISM /Online /?,  I have not messed with this in years but I would use extreme caution with this and would recommend you have a backup of your system first I use Macrium Reflect.

Some common DISM actions once you have good backups:

Quick Check of your system

DISM /Online /Cleanup-Image /CheckHealth
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Comprehensive Scan

DISM /Online /Cleanup-Image /ScanHealth
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Restore Corrupted Windows update files

DISM /Online /Cleanup-Image /Restorehealth
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Then, if DISM did find corrupted files, you should run SFC (System File Checker) to repair any bad files in use with the updated images:

System File Checker

sfc /scannow
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After all of this, reboot your machine and hopefully you'll see better performance. However, as anytime a Windows Update is applies/re-applied, you should go through and ensure the update didn't mess with performance settings, as Richard pointed out in the video.