When was your last professional cleaning?
That's right. Just like your teeth, your brass instrument needs occasional maintenance by a professional service technician. Over time, breath and saliva will build up calcification in the horn (just like dental plaque on teeth) which cannot be removed with just warm soapy scrubs.
Once or twice a year your brass instrument will play and sound better, and be healthier after receiving a chemical wash from a brass service technician. Call and find out everything you would like to know about professional cleanings.