In my case I mostly provide the service for the benefit of local hams that have problems with noise on their home receivers during HF nets. Of course most of the connections are from all over the place/world and it is difficult to tell what most are listening for or to. Now that VE3SUN has been providing connections to KiwiSDR receivers from current DX-spots, I've started paying more attention to listening on the KiwiSDR. I'm looking forward to a better interface from VE3SUN to the KiwiSDR.
Of course I do catch new stations on the waterfall and add a tag for them just to remember that I have heard them there before.
You might not need to filter any complete bands, you might find you have 1 or 2 nearby stations that have strong received signals at your location. I would set the WF max slider for 0dB, go to the MW broadcast band and set the waterfall for "zoom to band". Then turn on the Spectrum switch. I would then look for signals peaking over -30dB and definitely take note of signals approaching or above -20dB. Then I would make a LC series filter from the feedline to ground for that frequency. The greater the L value, the narrower the notch. A LC filter calculator can be found here:
For example a series LC filter with 3000 picofarads and 4.4 microhenrys should filter 1380Khz down an additional 15dB or more, and if it were a -20dB it would now peak at -35dB.
I have not tried this, but I've read that if the input impedance to the filter is increased at the input and then decreased at the output, notch will be deeper. Such as a 1 to 4 step up transformer at the input, and a 4 to 1 step down transformer at the output. (50 ohms to 200 ohms).