Wet a white cloth with rubbing alcohol.
Dab the smudge to remove as much pigment as possible.
Repeat Steps 1 and 2 with mineral spirits until the color is removed.
Use tweezers to gently pick any solid oil pastel out of the carpet. Wipe the tweezers between passes so that the pigment doesn't return to the carpet.
Trim the surface of the carpet in the stained area, making short snips to avoid cutting too deeply.
Reexamine the area often to determine progress.
Pour enough soda water on the smudge to dampen it. Sprinkle with table salt. As the salt absorbs the liquid it will absorb the pigment.
Gently sweep the salt into a dust pan to avoid marking any more carpet.
Repeat Steps 1 and 2 until the salt fails to collect pigment.
Wet the corner of a white cloth with mineral spirits. Dab the smudge--don't rub--to pick up pigment. When one part of the cloth becomes colored, move on to a clean area.
Repeat Step 4 until the pigment is removed.