Apparently he didn't believe the advice but after his horrid first half with the Giants he was finally ready to try something else (after umpteen years of so-so success since his breakout first year) but didn't want to do it during the baseball season. However, with his time on the DL, he decided to try to use that time pitching in rehab to learn to do what Williams suggested. Obviously he succeeded.
The article also noted Tomko's tendency lately to pitch poorly in the first half and then better in the second half. To combat that, Tomko continued his exercise program during this off-season plus continued throwing off the mound. His thought is that it takes him up to half the season for his mechanics to be perfected, resulting in him doing better in the second half. He is hoping that being ready when the first pitch of the season is thrown will allow him to get in his groove from the get-go instead of taking half a year to get in his groove.
However, most articles and commentary talk about his 11-4 record in the second half of 2003 - plus noted his talking with an old coach then at Toronto and getting advice - but missed something very important about that: his ERA was really not that great during his 11-4 run. I calculated his ERA during this period, which one would think would be as dominating as his low 3 ERA in 2004, but it was a very mediocre to lousy 4.62, which would only earn an 11-4 record for a great highly potent offensive team (which he luckily was on with the Cards). Oddly enough, he was dominating at Busch Stadium with a sub 3 ERA but beaten to a pulp on the road with a near 8 ERA. So while he was better in the second half vs. the first (5.60 ERA before he started winning for a 2-5 overall record at the "turnaround" point), it wasn't like a lightbulb turned on, it probably meant that he got more home starts while previously getting more road games (based on that huge split).
Hopefully, this secret is more concrete than just headshrinking and is related to his changing how he approached pitching and is augmented by how much better he takes care of his body this year. If so, we could have Schmidt-lite pitcher to go with Schmidt, which would be a key to winning a World Series championship as history have shown that having two dominant pitchers going - and Tomko was dominating at the end of 2004 - increases the odds of going all the way. That coupled with Williams hopefully returning to his form in 2003 and Lowry being close to how he did last year and the offense being close to last year's second place finish, could mean another banner regular season close to 2003's record, if not better.