how can I remove the dirt / soot in the outside areas of my carpet?

Answer 1

It depends on what it is and also is your carpet a light color...cream or white? Do you burn a lot of candles that are not soot free? Candle soot gets into the heating/air system and distributes it to the edges of the carpet and is impossible to get out. Soot free candles cost more but if this is your carpet problem, you may want to rethink what you have been burning. This would go for anything that you use that creates soot. FYI....Yankee Candles spits out the most soot of any candle I have burned. That is what created my problem. Tried professional cleaning. All carpets will be replaced shortly.

Answer 2

Sounds like you have whats called filtration soil. Filtration soil is carbon that is often released from appliances like your HVAC. It is pretty common and creates black on the outside of the rooms and doorways.

Filtation soil can be removed by most professional carpet cleaners.

Find a cleaner who uses pro's choice. They make a very effective filtration soil remover called FSR