These days we have the advantage of installing flexible stainless steel liners to woodstove inserts and to oil furnaces.
Flexible stainless steel liner kit. I think it is important that only a poly brush be used for cleaning. A brush made of round or flat wire brush could rip the liner if it encounters an acute angle in the liner. Sometimes a liner is installed at an acute angle somewhere in the chimney flue. Poly brushes are much more forgiving than wire brushes.
A 24-year veteran of the chimney repair trade, Cliff has experience in most phases of chimney construction and repair. He began as a chimney sweep apprentice in 1991. Two years later he began to educate himself in bricklaying and chimney construction. He claims that "it has been an interesting trade to say the least.."