I use aspen as well...
I clean everything thoroughly, every 3-4 months (that is with spot cleaning whenever necessary).
Like mentioned above, if I see an area that is really soiled, I take it out (the furniture), clean and replace some aspen in that area.
What 'lyndy299' mentioned is a valid point as well...
I consistently monitor the water dish and never over fill it. This helps to reduce the moldy/damp smell, plus reduce the chance of mold/bacteria growth, which contributes to less cleaning overall.
I clean everything thoroughly, every 3-4 months (that is with spot cleaning whenever necessary).
Like mentioned above, if I see an area that is really soiled, I take it out (the furniture), clean and replace some aspen in that area.
What 'lyndy299' mentioned is a valid point as well...
I consistently monitor the water dish and never over fill it. This helps to reduce the moldy/damp smell, plus reduce the chance of mold/bacteria growth, which contributes to less cleaning overall.