Sorry, I could not view the topic 60min before the solution has been posted.
I believe that by "without iterations" he meant something like:
manager.BatchRemove<TAccount>.Where(Linq['Balance'] < 0);
and/or
manager.BatchUpdate<TAccount>
.Set('status','inactive')
.Set('CurrValue', Linq['OpeningValue'])
.Set('StateChangeTime', now)
.Where(Linq.LessThan('balance', 0));