If I have a combobox with the multiple selection with labels ["Option 1", "Option2", "Option2"] and values [1, 2, 3]
There is no way to use these values in SQL query without converting them to string. You even suggested the "solution" and yes, it is possible to use FIND_IN_SET, but they are all about data conversion.
delete from dbo.users
where id in(SELECT value FROM STRING_SPLIT({{ BulkDeleteRows.value }}, ‘,’))
You know at the moment of SQL statement preparation that one of the placeholders is the array, why you cannot just serialize it as is? There are only 2 types of data that could be used number and string, just add numbers support.