Comments on my MultiDB Setup ?

Hey guys i know this is the best place to ask

I am sitting with a BIG Multi DB setup Here is the list of the db and there sizes

2.1G blogline_0
1.9G blogline_1
2.4G blogline_2
2.9G blogline_3
2.7G blogline_4
2.7G blogline_5
2.1G blogline_6
2.0G blogline_7
2.3G blogline_8
2.4G blogline_9
2.0G blogline_a
1.9G blogline_b
2.3G blogline_c
2.2G blogline_d
2.0G blogline_e
2.2G blogline_f
297M blogline_global

1) First Problem MySql dont like to load up BIG dbs it hangs and then the page just goes white

I need to clean up the DBs i want to remove all comments form all blogs

So what i need is to have a plug or script that can do this for me.

Please guys i know some one out there has set this up for a customers please let us have it so we can use it with our Multi DB setups please