Answer:
use baby wipes to clean the outside. use a cu-tip to gently get the inside clean. this is the cheapest solution other than to get an expensive cleaner or to take them to the groomers.
--------------------------------
You can use baby wipes for the inside as well, just make sure to wipe up the moisture with a cotton ball or cotton pad. Any vet will tell you that Q-tips are NOT recommended for dogs' ears. Use a large, soft ball of cotton and really clean deep into the ear. Their ear canals are different than ours, so you will not harm the ear drum. Ask your vet at your next visit to show you the best way to clean the ears.
If you prefer not to use baby wipes, you can buy a cleaning solution from the pet store or your vet. Again, just make sure to wipe out any moisture with a dry piece of cotton afterwords.