What a lot of folks wind up doing is have dedicated atomizers for certain "families" of flavors. For example, an atomizer to use with fruit flavors, a separate atomizer for
tobacco, and yet another one for menthol. That way when you taste the old flavor, it's hopefully fairly complimentary with the new one, and eventually, the taste of the old passes.
Some folks rinse their atomizers--even boil them in hot water--then THOROUGHLY dry them out. I've heard folks using hairdryers on low settings. I may be in the minority, but I don't wash my atomizers, so I can't comment on how well that works. I killed an atomizer by cleaning it, so I just don't do it anymore (although in all fairness, it was probably on its last legs anyway).
Instead of cleaning the atomizer, I blow it out. I remove the cartridge then separate the atomzier from the battery. I then take some kleenex and roll a corner of it into a thin "finger," which I then stick in the barrel of the atomizer. I then gently but firmly blow on the other end of the atomizer (the end that attaches to the battery). Remove tissue and do it again until you don't have any more liquid coming out. Then, reprime the atomizer with a couple of drops of the new liquid and
vape away. This won't completely remove the taste of the old liquid, but it will shorten the length of time you have to vape through it.
