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.
Prevention and Control. 1  To discourage raccoons from visiting your yard, stow water and food supplies, such as pet bowls and bird feeders, out of reach at night.  Some homemade repellents that have used successfully are a dusting of baby powder, cayenne pepper, or blood meal on vegetables and corn ears.