macOS ACL settings - unable to delete Time Machine backup left-over files

(macOS Ventura - MacBook Pro M1) I have deleted Time Machine backup file manually!! (my bad). Now I am left with files in my .Trashes folder that I cannot delete, no matter what I try. I have enabled root user; I have disabled SIP; I have tried chmod -N, chmod -/+a, chmod 777 etc. to no avail... I have read a lot about ACL, extended attributes etc. but I couldn't find a solution. All of the files that I am not able to delete have the following ACL: For ex:

ls -le@ah WebSecurity
-rwxr-xr-x@ 1 root wheel 222K Aug 15 2019 WebSecurity
   com.apple.finder.copy.source.checksum#N 4B
0: group:everyone deny write,delete,append,writeattr,writeextattr,chown

Any help will be appreciated a lot :) I have tried the following on this file:

sh-3.2# chmod -a "group:everyone deny chown" WebSecurity
chmod: Failed to set ACL on file 'WebSecurity': Operation not permitted

sh-3.2# chmod -a "group:everyone deny writeattr" WebSecurity
chmod: Failed to set ACL on file 'WebSecurity': Operation not permitted

sh-3.2# chmod -N WebSecurity
chmod: Failed to clear ACL on file WebSecurity: Operation not permitted

sh-3.2# sudo chmod 777 WebSecurity
chmod: Unable to change file mode on WebSecurity: Operation not permitted