Just joking about the 30cm pipe cleaners ... personally only use them on briar churchwardens.
I don't find it necessary to use any cleaners on clay churchwardens and apart from providing a great smoke they will eventually colour wonderfully well:-
Seattle Pipe Club's Potlatch. I recently became an instant fan of their Plum Pudding, and it made me want to try some more of their blends. Potlatch contains, from the label: black cavendish with luxury burley, Cyprian latakia, bright Virginias, Turkish, Orientals and Acadian perique.
I get a taste of the burley with maybe even a little cocoa. The Perique is there but you have to kind of search it out; it's not as pronounced as in Plum Pudding. There's a smokiness and maybe even a barbecue-like taste from the Latakia--maybe helped along with the black cavendish.
The tin I received looks to be a couple of years old, as it has no obnoxious warning label on it. There are at times some rough spots but overall a very enjoyable smoke. I've already ordered more.