Switching clefs is not uncommon. It can provide notational convenience when a part shifts to a higher or lower range than the current clef easily encompasses. However, the piece you've posted is an exercise in reading clefs and quickly shifting between them. It's highly unusual, but useful for training as a conductor, for example, where switching from clef to clef within the various parts of a score is necessary.
As an aside, here's a Wikipedia note on the composer.
Example 1: Reading as a conductor
Here's a typical, uncomplicated example of the demand made on a conductor. There are three different clefs to be scanned. (The excerpt is from Tchaikovsky's Sixth Symphony and begins in the first movement, seven bars after rehearsal A in the linked score.)
Note that the treble-clef instruments are notated in different keys, because of the instruments involved. So not only does a conductor need to clef-switch, but must also transpose within a clef.
Example 2: Notational convenience
Compare these two editions of Chopin's Etude in A minor, Op. 25 No. 11. Both images are of measure 11.
This first image comes from the Pachmann edition. Note that the pitches are written in their canonical staff positions.
Contrast this with the Paderewski edition, in which the highest notes in both staves are altered: the right-hand (upper) staff with an ottava, and left-hand (lower) staff by a temporary change of clef from bass to treble and back.