Hey Mr. Bream.
So I only use Murphy's on pipes that are sandblasted, rusticated, or have plateau tops. This because when used in conjunction with a tooth brush it gets into the nooks and crannies and lifts the tar, oils and carbon fairly nicely. When it comes to smooth pipes I use the following methods:
To Lift Carbon & Tar From Rims
1) Place distilled water in a saucer until it is 2mm-4mm deep
2) Set bowl rim down in distilled water and allow it to soak for 60 seconds
3) Remove bowl from distilled water and rub the rim with a cotton tea/dish towel
4) Wash, rinse, and repeat until carbon and tars have been removed
To Clean Oils, Grime, Smoke Residue From Smooth Stummel
1) Rub down stummel with a wet tea/dish towel to remove surface grime
2) Evaluate whether further cleaning is required, understanding that using anything other than water will lift some stain
3) If further cleaning is required, use isopropyl alcohol on a cotton ball or cotton cleansing pad and wipe down the surface of the stummel allowing the alcohol to evaporate in between applications
4) Evaluated whether further cleaning is required, if so, repeat Step 3 or repeat Step 3 and substitute acetone for isopropyl alcohol
To Take A Stummel Back to Natural (or close) Condition
1) Remove the stem
2) Soak the entire stummel in a bath of high % grain alcohol overnight
3) Remove, rub clean, and allow the pipe to dry for 24 to 48 hours before doing any further work
For a thorough walk through these and other techniques, take a gander at the blog http://rebornpipes.com/
-- Pat