Yeah, the 10% is awful. I'm afraid I don't see the point of resetting to something almost as bad.
Why not create default growth tables based on total size, one for data and one for logs? Typically a size of anywhere from 5-20% works well for data and/or logs, modified to take into account existing file sizes, disk space available, etc..
SQL DBA,SQL Server MVP(07, 08, 09) Prosecutor James Blackburn, in closing argument in the Fatal Vision murders trial:
If in the future, you should cry a tear, cry one for them [the murder victims]. If in the future, you should say a prayer, say one for them. And if in the future, you should light a candle, light one for them.