Unless you have VERY dirty fish, you won't see much after a month. A 404 could go for 3-6 months without cleaning.
The ribbed hose is junk. If you can replace it, do it. There is a lot of pressure loss when the ribbed hose goes over the tank.
I havn't cleaned my hoses in a year or more. Its only on my 29 gallon but all there is, is alittle crap built up on the edges but when I prime the filter after cleaning, the air and water being stirred up usually helps to clean them out anyways, atleast the output.
The ideal thing to do would be to replace them.