i had a really long post prepared but its gone now ~_~ time to retype i guess
if i had to guess, axe's answer would be to keep a tight dashdance close to jiggs so that you can sneak in a nair (or usmash/uair) during openings
if they're doing low WOP (wall of pain, aka bairing a lot) far away you can throw out jolts if you want. they dont tack on that much % though and it usually doesnt change the neutral game that much...jiggs can just start WOP'ing again
often if you want to punish WOP directly you'll have to nair preemptively by calling both jiggs' air movement and bairs. you can make this easier if you try to look for the jiggs' tendencies: how he weaves during bair, how many jumps he likes to do before landing, how high he likes to WOP, how he spaces bairs both distance-wise and time-wise, etc. stuff like that. patterns arent the most reliable thing though so take this with a grain of salt
keep in mind that trying to nair against WOP is pretty risky and personally id suggest against it unless you're confident in your reads. also keep in mind if jiggs can call your nair attempt they can just dj over it during WOP to completely neutralize it. you can also fire nairs from side platforms vs higher WOPs/jumping, but this limits your nair trajectory a lot and can be avoided pretty easily. again, i would suggest against nairing into a WOP...I usually wait for when the jiggs lands or goes high
trying to call when jiggs lands and doing a crossup nair then works pretty well since jiggs doesnt have the best grounded options (especially if your dashdancing is tight). keep in mind jiggs can throw out a smash attack or something similar against your nair if they see youre trying to punish landings, but this is made harder if youre close to the jiggs
you can try to trade with your usmash once jiggs is around killing % (even if its slightly lower, you could followup with thunder). dont trade with nair though lol. if youre feeling ballsy then you can try to powershield usmash but that's hard, shield usmash oos works too
for your reference:
axe vs hbox
http://www.youtube.com/watch?v=741XSWhw0M0
http://www.youtube.com/watch?v=gwaMx4-wrkw
http://www.youtube.com/watch?v=L7wwkaFa6A4
(as you can probably see, playing vs good WOP'ing is pretty damn hard)
B-Air
Total: 39
Hit: 9-12
IASA: 31
Auto cancel: <8, >25
Landlag: 20
Lcanceled: 10
btw even though i suggest against punishing directly vs WOP i think it's possible to do it on reaction:
if you try to react to jiggs' foot coming out on frame 9, he has a minimum of about 20 frames of downtime, and another 5 frames of downtime before he can pull another attack out (this is assuming a perfect autocancel into a fast ground attack, which would be faster than another aerial). human reaction is around 15 frames, nair takes 4 frames to jump and 3 frames to come out for a total of 22 frames, with a few leeway frames to hit with the later hitbox. you want to look for times of lag to enter with nair.
jiggs' lag times:
lcancel takes 10 frames
autocancel takes 4 frames
jump takes 6 frames (and another 9 frames for a bair to come out)
o man i typed way too much ~_~ this alawys happens for some reason
tl;dr tight dd into nair punish vs WOP, trade w/ usmash or shield>usmash oos at higher %