When I play I generally allow both players are allowed to use the dictionary whenever they want (whether or not it is your turn), for whatever reason. You can combine this rule with time controls (there are a few possibilities for time controls, one way is to use chess clocks); if you take too long to look up the word while it is your turn, you are penalized by the time controls.
That swapping rule look like a interesting variant. A variant I have though of is that you can change the meaning of blanks on the board at any time during your turn as long as they are still valid words (valid both before and after your play, with the same letter being represented in both cases); this avoids having to remember what letter it is supposed to be. Another variant allows you to rearrange the letters of words you extend; if that changes words you cross, you score for the new words it makes. The mention in the article of removing bingo also can be a variant.
That swapping rule look like a interesting variant. A variant I have though of is that you can change the meaning of blanks on the board at any time during your turn as long as they are still valid words (valid both before and after your play, with the same letter being represented in both cases); this avoids having to remember what letter it is supposed to be. Another variant allows you to rearrange the letters of words you extend; if that changes words you cross, you score for the new words it makes. The mention in the article of removing bingo also can be a variant.