Indeed! Individual Catholics who feel the need to avoid the practices of other religions can certainly do so, but to say that this must be so for all of us runs counter to the teachings of our Church. Consider this from the 1984 Vatican document, The Attitude of the Church Toward Followers of Other Religions:
**"The Dialogue of Religious Experience:
At a deeper level, persons rooted in their own religious traditions can share their experiences of prayer, contemplation, faith, and duty, as well as their expressions and ways of searching for the Absolute. This type of dialogue can be a mutual enrichment and fruitful cooperation for promoting and preserving the highest values and spiritual ideals. It leads naturally to each partner communicating to the other the reasons for his own faith"**
And of course there’s this oft quoted chestnut from the 1989 Vatican document, On Some Aspects of Christian Meditation:
"That does not mean that genuine practices of meditation which come from the Christian East and from the great non-Christian religions, which prove attractive to man today who is divided and disoriented, cannot constitute a suitable means of helping the person who prays to come before God with an interior peace, even in the midst of external pressures."
and also,
"These and similar proposals to harmonize Christian meditation with Eastern techniques need to have their contents and methods ever subjected to a thorough examination so as to avoid the danger of syncretism."
This last teaching, I think, answers the OP’s question, how far is too far. The prayer practices of other religions can be of beneficial use to us Catholics who feel drawn to them, provided we are grounded in our own faith, and do not stray into syncretism (the idea that one religion is as valid as another, or that all religions are ultimately the same).