The problem is the thread of the swab (6 * 100) which is not common at all and therefore impossible to find a control rod however essential to use the swab.
So I finally ordered 1m threaded rod at the right not on a dedicated site (not available at Casto, LeroyMerlin, Bricodépôt and other GSB) ...
Too bad.
I'll better off purchasing a swab of the same diameter with stem.