i'm calling tl:dr, so sorry if i get redundant in this post
i tend to use band-stop filters to mitigate whistling and EQ'ing in woohoos. the crowd artefact worked upon will sound weird and unnatural, albeit more comfortable to your hears. whistlers are *really* easy to remove almost completely with a very favorable compromise in music loss. if you determine the fundamental frequency of the whistler using a narrow Q, high boost, and sweep in your softwares parametric equalizer, you can determine which frequency the whistle has and BSF the fuck out of it. .the narrower the BSF, the least ammount of music you affect and the results are pretty good if you're rigorous and most of all patient. and since most whistling is between 2.6k and 3.5k, you can easily isolate and determine accurately where it is. (DO NOT cut everything between these values, just search for the frequency where the whistle is located). another much more effective method of detection is using the spectral view function.
you'll find a hot region around 500Hz and 800Hz for most male woohoos, a little higher for girls. however, a lot of music is located inbetween those values, and i would not encourage the use of BSF for them. just use a realatively soft EQ in that region and you should get pleasing results. heck, even if you lose some music in the process, its much better than suddenly having a guy screaming at +6dB the normal music program of the recording. bottom line, BSF for whistling and a rather conservative EQ for woohoo.
you can also attenuate the harmonics i both cases, but thats a whole different subject and i wouldn't recommend doing it in either cases as it would further damage the music in the recording (especially if you're talking about woohoos). the only time i used such method was in a case of extreme feedback, and i used a notch filter there.
for handclaps, limiting is the best. if you're reeeeealy patient, i suggest you work clap by clap. pay attention to the difference between the snare attacks and claps, as they are easy to confuse on the waveform display.
PS: most conservative guys would probably argue with some of the methods described above. i don't like the extra work, so hey, if they are to be used, make it a special case. living in a latin country, crowds can go wild sometimes and most of my tapes would be unlistenable unless i applied some of the extreme editing described above.
examples (done in a sloppy quicky way)
whistle
post-whistle