Can anyone recommend a good silver fish groundbait for commercials

The target species are roach and skimmers mainly with the odd perch thrown in. Would you add any bait to it such as caster etc

The depths vary from 4ft to 9ft deep.

Also how would you feed the groundbait to start and how many lines would you put in.

Many thanks

P.S

I can’t remember the name of the venue so can’t find any thing on google