Yes, bagless cleaners should be washed out on a routine basis, or they do start to smell, especially with pets. I have washed out my Dysons, and everything except the electrics, brushroll and motor goes through the washing up bowl. The hoses also go in the washing bowl with just plain water and washing up liquid. I leave the hose to soak for an hour or so, then with the ends still held under the water, I lift the centre of the hose out of the water and stretch it out, so filling the hose - this reveals any small holes as well - you see air bubbles entering the hose at the point of the hole. Then I lift the ends out of the water and let the water drain back out of the hose, taking the crap with it. I repeat this several times. Then I take the hose out in the back yard, attach one end to a hook, and then stretch the hose to full length and attach the other end to a hook higher up than the first, so the water drains down the hose, and air can permeate it to dry it out.
I wash out the bins, cyclones, but not the brushroll, just wipe that over and avoid getting water in the bearings.
If your filters are washable, wash them regularly, but if they are paper pleated ones, dont wash them as it will ruin them. Paper filters must be replaced when dirty.
The most important thing with washing a bagless cleaner's parts is letting them FULLY dry before further use. If water gets in the motor, its not good.