Without invalidating kingofdating com
The notes of an Altered Dominant in C Major, starting on b2 would be Db (1), D (b9), E(#9), F(3), G(#11), A(#5/b13, depending on who you ask), and B(7), though Jazzers would often spell it enharmonically to line up with the chord tones described in parentheses above (Db, Ebb, E, F, G, A or Bbb (depending on who you ask), Cb).
This allows you to use a TT for just about any diatonic melody that appears over a V7 chord without creating major conflicts with the melody, however, it is still a different chord and one that is rather dissonant, so it should be used with care outside of its standard Jazz setting (or even in Jazz).
The common tones between two chords may not be enough to justify a substitution.
For instance, if you were to choose to substitute iii for I, then you will want to pay attention to whether or not the tonic is in the melody since that is the one note that is not shared between the two chords.
Are you trying to maintain strict counterpoint, just reasonably consistent voice leading, or just keep it sounding fairly consonant behind the the screaming Gilmouresque Strat/bebop saxophone/ambient Frippertronics solo you already recorded over the unmodified progression?
My answers to those would be "probably not", "maybe", and "probably"/"yes"/"it doesn't matter" (screaming Strat/bebop Sax/ambient Frippertronics), respectively.
I always like to remind people that music theory is not so much a set of rules, as many are often taught, but an explanation of what is happening and a language to discuss it.
Theory is basically only rules when you are trying to authentically imitate a specific style, so you will actually find that there are different "rules" in this regard for different genres.
Same with 2 of the TT being ^#2 (b3), which could conflict with ^2 or ^3, or 6 of TT being ^#6 (b7) and conflicting with ^6.
On the whole, like with all theory, you should be using your ears more than subscribing to some rules.