h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

1- Brute force method: Cut the stained part out and burn it. You replace the stain with a hole. (Liverspots and other nauseating things can be and are efficiently removed in that way)

2- Chemically alter the properties of the stain (in its character as a dye) so it is not visible (and thus cannot be defined as a stain). This process is also commonly called bleaching. Sometimes this method can be quite similar to the first one especially when the stained substrate is dissolved by the chemical. White clothes can be easily freed of stains with hydrogen-peroxide or sodium hypochlorite. (These reagents will destroy the dye-molecules). The remnants of the destroyed stain will still be contaminating the spot, but at least it is invisible.

2b - Physical processes like electric or photonic interactions work pretty much in the same way.
(I could write more about this if desired)

3- Dissolve the stain. This method is probably the most prevalent one. Stains can be dissolved by:
a) pure Water (if the stain soluble)
b) Soap (the way soap works can be checked out in the "How does soap work"-Entry)
c) Alcohol, Turpentine
d) Saltwater
All of those work pretty much the same way. Precautions are to be taken if the stained substrate is not to be damaged. As an extension there should be included: The dissolution of metals in mercury. Nitroglycerine and TNT could be thought of as good dissolvents, but those chemicals have some undesirable collateral properties.

4- Transform the stain into a pattern, so it is no longer reckoned as a stain. Example: Some ink droplets stain a piece of paper. Use a biro and incorporate the droplets in a drawing, so it looks like they're there on purpose. The stain is away!

5- Other methods:
Wine stains can be removed from cloth efficiently by pouring salt an the stained region (the salt absorbs the wine)

Remark: Should greater-scale objects be considered as a stain too? For example a ugly building in a city? Or the craters on the moon? Atolls in the pacific (which are readilly removed by an atom-bomb or two)?

And microscopic-scale stuff? Like single impurities only detectable by the use of microscope (like mites on the toilet-paper)?

There is more to be discussed, I think... Please post.

Wonderful!

Too late! This whole entry will be too late for the case of a former president of one of the major countries of this planet. Had he known how to get rid of (err, wording would be removed by monitorer) stains...
And "colouring" the rest of the corpus delicti in like manner wouldn't have been a solution either...

Well... while we're on the subject of stains, many of my liberal friends (what better kind is there?!), as well as myself, regard our current leader as an accidental blemish... and his mistakes (e.g., ineptitude and his less-than-honorable record of business dealings) have been far more relevant to the presidency than those of his predecessor.

just my opinions, of course, as I suppose I am obligated to say...

Sorry to butt in on your conversation, but if
Researcher "An Ambling Rambler"
would go back to there own page and then click on the "EDIT PAGE" button and then write a little something about your self then a ACE can come and welcome you there properly
Sorry for interrupting your conversation

Manda

heh heh, sorry, I'll edit the page soon, I just joined yesterday (the day I posted the above).