MacOS filetype question and or tip

[MisterX]

I think someone earlier was saying we couldn't change filetypes on the
mac...

The revdocs say this for "filetype"

in the comments

The fileType property is used to set the file type and creator of files
created by the open file command and of files created putting data into a
file, binfile, or resfile URL that doesn't yet exist. (To specify the file
type and creator for stack files your application creates with the save
command, use the stackFileType property instead.)

if i read that correctly, and after setting my filetype property, any file i
write to will be changed to that type and creator right?

TIP:
To change a file to another type easily, just open it, append empty to it,
close it... would that work?

too bad they didn't think of 

"set the filetype of file myfile to "xxxxyyyy"

cheers
Xav