It’s 11 p.m. on a Tuesday and you’ve got that I-showed-the-mildew-who’s-boss glow … when the doorbell rings.

It’s your younger brother. In town with his band and looking to crash. Familial piety makes you relent, but you cringe inwardly at the thought of your immaculate nest getting sullied by his icky entourage.

Not the groupies — the nasty muck on his shoes.

Get Dr. Doormat, an antimicrobial welcome mat that’ll do away with at least some of your worries. Harmful dust enters houses on the bottom of shoes, often aided by the germ-harboring tendencies of most doormats. Once inside, the noxious particles fester and multiply, causing all sorts of unpleasant reactions too gross to mention. (Trust us.) Dr. Doormat works like a bouncer, barring pollutants, bacteria, and carcinogens from entry. A simple wipe-and-scuff on its toxin-neutralizing surface removes virtually all such riff-raff, eradicating its hazardous capabilities.

If only turning away all uninvited guests were so easy.

Available online at drdoormat.com.