Using pocket diapers as covers?

ReneeDear

I was on the AMP website today and it said that you could use their pocket diapers as covers and just replace the insert and reuse the cover.  

 I've been using Bummis Whisper Wraps and prefolds on my son.  He is approaching medium sizing but I have not been able to find any used diaper covers for sale. I'm on a super restrictive budget right now so I'm looking for the most inexpensive option. My husband really likes the covers because he can just dump the prefoldinto the bag without touching it.  

I'm thinking of buying some one size pocket diapers (like bumgenius) and using them as covers.  That way I won't need to buy as many. I was wondering if any of you used the pocket diapers this way.  How did it work for you?