DTS and jobs mamagement

i inderited a few servers with 800-900 jobs and around 1200 DTS on each

I want to cleanup whatever is not used

I was successfull in deleting some of the disabled old jobs it was all manyal and tidious and basically eyeballing everthing

Is there a better was if some one can suggest please?

How would i figure out what DTS are never used in any jobs?
in most of the DTS loggin is not enabled?

Can someone suggest a better more efficient route of doing this?

Thanks