Freezing Avocados

We love avocados in our house...we eat them with Mexican dishes, make lots of guacamole and even use them as a substitute for mayo on sandwiches. I like to stock up when Kroger has them 10 for $10, but unfortunately, sometimes we don't eat them fast enough.

On Pinterest (of course), I saw someone who froze their avocados. You cut them in half, take out the pit and wrap in saran wrap and then place in freezer bags. 

I'm not sure what I did wrong, but my avocados came out of the freezer brown and as I let them de-thaw, they got even browner :( I think this is a great concept, but I'm not sure it's possible...anyone else try freezing avocados? Any tips??