my candy washing machine sometimes smells of bad eggs during the wash cycle?

Not certain but you might have a build up of sludge (between the drum and its container, also in the pipes) from washing detergent, dirty laundry and the natural minerals that are the cause of water hardness, that is coating the inside of the machine (this is fairly normal).
You might try doing two or three cycles on the hottest setting without any laundry in the machine but add a 200 grams of soda crystals (sodium carbonate) instead of washing powder for each wash. You should repeat this cleaning process if the machine starts to smell.
The sludge often forms when the wrong amount of washing detergent is used (I think normally too much) but also depends on the degree of water hardness. Adding a teaspoon of Soda Crystals to each future wash will decrease the water hardness in much the same way as more expensive water softener products allowing you to decrease the amount of detergent used (should also increases life of machine).
Also check the temperature that you are washing at with the detergent that you are using - biologicals do not work at higher temperatures so raising the temperature would make them wash less effectively or not at all. You should try to do a very hot wash with a non-Bio detergent at least once every ten low temperature washes as this should help kill any bacteria and also possibly help to dissolve parts of any sludge.
Also when you have finished washing leave the door slightly open so that the drum can dry out - bacteria which cause the smell (Hydrogen Sulphide I think) would be feeding on parts of the sludge and they prefer damper environments.
This may not cure your problem straight away but should help in the long term. The sludge will have taken time to accumulate and will also take time to get rid of - unless you take the machine apart and physically clean all surfaces.
Check your detergent drawer to ensure that it too is clean and not clogged - take out drawer and check inside the machine space (where the drawer was) to ensure that it is not mouldy.
Final point (if you can) check the drain pipe ensure that it allows free flow of discharged waste water.
Hope this helps.

Flying Fox
October 2009