Basement waterproofing is accomplished from the Exterior. By the time you let water in, you’ve got big issues.

As usual, Live Wire is right on. The unavoidable fact is that cinderblock is permeable. Nothing you apply to its inside will change that, even expensive specialty paints that claim to "become an integral part of the concrete mass."

If you really have proper waterproofing on the outside of the foundation (pitch/sealer and membrane applied to the block all the way down, un-clogged footer drains with sump and sump pump), you've already done as much as you can do to cut water passage through the block.

The next step is to reduce ground saturation around the house. Make sure that your roof gutters are clear, and that they drain well away from the foundation. Ensure that the ground around the house slopes away from the foundation. If you have problems with surface wash during heavy rains, add swales to channel the water around the house.

If you still have high cellar humidity after that, about all you can do is remove it faster - buy a bigger dehumidifier, or add a second one. Shame they use so darn much electricity.

Covering the exposed block wall with extruded or expanded foam board followed by drywall will reduce the dampness from condensation that comes from moisture-laden summer air hitting cold foundation walls.

Before Delta membrane was available in Canada, I used crystalline waterproofing applied from the outside on poured-in-placed walls. Since then, the standard is membrane over asphalt cutback dampproofing

Mechanical dehumidification is a must. No magic way to reduce condensation. During summer, our dehumidifiers run 24/7.