Most people don't think about the cleanliness of their washer and dryer - after all, the one has soap and hot water flowing through it regularly and the other is full of hot air. :) How dirty can they get? The answer: plenty dirty! While they should be cleaned at least yearly, if you have have a family member with allergies, then it might be a good idea to do it more frequently due to the mold that can build up in the washing machine.
The washing machine is fairly easy to clean, but there are a few tricky places. We'll start with the easy ones first. Obviously, anywhere that you are PUTTING things IN to the washer (detergent, fabric softener) need cleaning. Usually they build up and and can actually start growing mold if you don't catch it. Try to take apart anything that you can easily do so. Feel free to wash them in warm, vinegary water. This will take out any lurking odors. Also, if the build-up doesn't come off easily use a toothbrush designated for cleaning. You can also try a bottle brush (made for cleaning baby bottle nipples, etc). Although sometimes it won't give you the same 'hardness' that a toothbrush does.
Another easy place to clean is the actual basket of the washer. Feel free to start your washer, add some vinegar and/or baking soda and then right before it cycles for washing turn it off. This will give you all the time you need to scrub it. You can use a soft wash cloth or your favorite cleaning tool. Usually this part of the washing machine doesn't get to bad due to the friction of the clothes rubbing on it. However, it never hurts to give it a good scrub!
The trickier areas are the ones that are hard to reach. Where the water actually comes out - this is a great mold breeder! A nice tool for this is a toilet brush that has the lip brush on it that can reach those hard to reach areas. (Just make sure it hasn't been used in the toilet!) Another area is the fabric softener place. Usually you can only reach so far to clean it. I usually try hot water and pour it down that channel and use a long brush (bottle brush) and try cleaning it that way.
Your dryer is actually fairly clean. However, it doesn't hurt to give it a good cleaning now and then! The lint trap is a nasty thing that if you don't clean it out regularly (at least yearly) you can have a lot of wasted energy costs, threat of fire, etc. You need to vacuum it out - all the way to the outside of your home. If you can get it all out your dryer will run so much better. The actual lint trap should be washed out or vacuumed out thoroughly. If you want a heartier clean, use soap and water on it, making sure to rinse thoroughly! You don't want to cause build up on it!
How often you choose to clean your washer and dryer is up to you, but, you will be glad that you did!
Make it a great one!