It takes a process, but you can use a very diluted bleach water solution. Use 1 part bleach to 10 posts water for the tank and the hard, n non-porous parts of the filter. Wash it all, then rinse very well several times. Make sure everything dries out thoroughly before you use it again. If you start to use it and the bleach smell comes back, you haven't washed it off enough, go back acne rinse it all really well again.
For the travel and anything porous, I would suggest gently boiling it for 10 mins or so. Make sure it has thoroughly cooled before you return it to the tank. I wouldn't suggest boiling anything plastic, unless you are super careful and watch it the whole time. Use plenty of water in the pot, and make sure it doesn't rest on the bottom of the pot... But again, NOT recommended as you could(at best) end up with a melted item, and at worst burn the house down.
Vinegar water also works to clean stuff, but again, it needs to be well rinsed.
Maybe someone else has other suggestions?