Paragraph 22 discusses the notions of chastity in that the general idea is to condemn various methods of sexual expression ("social communication which arouses men's baser passions") as it promotes a poor environment and future for humanity ("the need to create an atmosphere favorable to the growth of chastity so that true liberty may prevail"). Essentially what is being constructed is a social movement to remove aspects of sexuality which have negative impacts upon the "human spirit".
This means that pornography, nudity, sexuality, anything that is textual or visual or even suggestive in nature which intends to incite sexuality in individuals is downplaying the progression of humanity and society. This argument is rather assumptive however in that such media causes stagnation in society, or that we will be 'distracted' from being productive members of society. And there is some truth to this, but at the same time we must also remember that in doing so may curb the sexual needs of individuals. At the same time, this may also incite individuals who are not satisfied by such presentation of sexuality to negatively impact others in various ways.
However, where this argument takes it's turn is the line "it is quite absurd to defend this kind of depravity in the name of art or culture or by pleading the liberty which may be allowed in this field by the public authorities." To promote your own culture's values for denouncing sexuality in media is perfectly acceptable, but we must remember that not everyone has this same outlook on life or 'human progress'. This comes down to our definition of freedom, which we can typically look at as being the ability to believe and act however you wish but without affecting the freedoms of other individuals. But the argument put forth in this paragraph can still be attributed to this notion, as said previously regarding a favorable atmosphere and "true liberty".
What it comes down to is that the argument put forth is valid, but only when looked at from a single perspective, making it unenforceable in a number of ways. In addition, these words can be twisted very carefully to imply that it should not be removed from society, but heavily looked down upon. "Should be condemned publicly and unanimously" does not imply removal of this aspect of society, and furthermore does not mention anything about the privacy of the individual, but simply focuses on public display of such aspects. Thus, using this logic, very little change (especially in the United States) would have to be made to actually abide by this ideology.
Overall, personally, I think that it's rather outrageous to try to enforce this on people. Most studies have shown that sexuality does not promote illegal action (rape, murder, etc.), and we should never forget that we are still 'human' (and all biological factors that relate to such a title) and if we put such restraint on sex and sexuality, it only intensifies people's desire for it instead of supressing it.