Voluntary Administrators appointed to TGS, page-8

the business called delisted.com.au provides a service (at a cost) for buying worthless shares so that capital losses can be crystallised. It is a reputable business.

Here is their link re TGS shares

https://www.delisted.com.au/company/tiger-resources-limited/

It also provides info re companies no longer trading on ASX.
I do not know if they will do CFD's for you or if you would find it worthwhile.