Inspired by https://data.stackexchange.com/stackoverflow/query/971299/search-comments-by-any-keyword-by-date. Comments near the top of the table are more likely to be useless because they will be shorter and are less likely to contain useful information. Please be aware that deleted comments might still show up in the results sometimes.
Also, please DO NOT auto-flag comments using this script. Not all of these comments are necessarily useless. Please check if the comment contains any useful information. If it does, do not flag it. Many if not all of these comments can be deleted from a single non-custom flag, so be careful.
Q&A for scientific skepticism
select top 1000 c.Text, c.Id as [Comment Link], c.PostId as [Post Link]
from Comments c
where Text like '%thank%'
and len(c.Text) <= 50
order by len(c.Text) asc