In such cases the weeps consist of small-diameter plastic, clay or metal pipes extending through the wall to a layer of porous backfill. Typically, weeps are arranged to direct water which may have entered an assembly from outside back to the outside.
A few of several safe household chemicals to use are vinegar, dishwashing soap and rubbing alcohol, according to an Oregon State University Extension Service publication called Using Home Remedies to Control Garden Pests, (EC 1586). The publication, complete with photos, is available free of charge online.
One mealybug home pest control is to scrape away any white residue and spots on plants leaves that you can find. Then, using a solution of one part alcohol to three parts water with some dish soap (without bleach) mixed in, wash down the entire plant. Let the plant sit for a few days and repeat the process.