Had a nasty slammer to clean in Alliston area yesterday – took over a pail of creosote deposits out.  Scrubbed the whole smoke shelf and inside of fireplace – owner is replacing insert with new one and adding a liner.  Some small glazing remains in some parts which are not possible to get out – once damper is out could do more if needed.  The real reasons for removal are to prevent creosote odours from coming back down and if a lot then a potential for a chimney fire exists as the liner still gets hot.. especially if a fire in the liner were to occur.  Slammers are nasty – create a lot of creosote – are a serious hazard and a code violation.  A slammer is a fireplace insert – typically an older one – pushed into the fireplace without a proper liner attached.  For the record these units often do not provide much benefit in the way of heat either and are often times a waste of wood, money and energy.  Replacing them is often more than worth the work and cost not to mention the safety which is added.  If you need a Chimney Sweep – call a Certified Chimney Sweep professional!