Importing sibling relationships

I want to import several thousand sibling relationships into our main products table to be used for cross selling opportunities. In short, when a user queries part a, then parts b, c and d appear in the relationship (and vice versa). I've created a text file with the records (2185 of them) running down the page, then the related records running across the page ([TAB] delimeted). This created a massive relationship table where it linked all 2185 records to each other of the 2185 records and not to those specified across the page? The documentation seems to tell me that this doesn't work through the import manager (can only use that to import parent/child relationships) so how do i get these cross sell relationships imported? Has anyone done this before???

Thanks muchly 😊

p.s. after a while i'll be able to start giving some answers too! (n00b here)...