It's a crystalline penetrant that clogs concrete pores. You may also want to consider increasing the number of foundation vents to promote air circulation that will carry moisture away. If you continue to see moisture after trying these cures, then you're not dealing with condensation. Runoff percolates through porous topsoil and then stops at the compact soil near the base of the foundation. Hydrostatic pressure forces the water through gaps or cracks in walls and footings.
Water also moves through porous walls by capillary action.
A damp crawl space or wet basement walls and floors just after a storm or as snow melts are telltale signs the problem is runoff. Look for ways runoff can enter your basement or crawl space. Check that the ground outside slopes away from your house at least 1 in. Next, check that driveway curbs are channeling runoff to the street. Look for unsealed cracks on the driveway surface, which can allow water to collect below grade.