Reusing SR Custom Lists - Chaning/Deleting Values

Reusing SR Custom Lists

We have a Service Request Custom List (cust_list2) that I would like to re-use. I'm not fussed on the data associated with this field in previous SR's. However for me to remove options associated with this field previously I get an error.

The selected value(s) ('value') is being used in one or more Service Records.
To delete this value, you should update the relevant Service Records first.

I have tried via sysaid to change this on multiple SR's but it does not seem to work. So I went to the database and change them directly, easy done, but this is not reflected on the SR in Sysaid.

I am changing 'dbo.service_req.cust_list2' is there somewhere else this is set per SR?

Any assistance would be appreciated.