If you want to use pots/knobs:

Intellijel's 1U Quadratt is great for manual CV control. You can control up to four CV signals. You need only patch the outputs to whatever you wish to control. But if you don't have an Intellijel case, you are out of luck.

Befaco makes a Dual Attenuverter in 3U that can control up to two. Yes, its man function in life is to attenuvert. But just like the Quadratt, when nothing is patched into the input, the CV offset will generate its own CV.

As far as CV, always read up on the devices CV out or input ranges when mating two things together. It might effect the range of control that you have.