Is it still viable? Builds/tips?

Is very viable!

Cloth+Pots
Wraith Camp with Rupture, Smite Blue Wraith, rupture once.
Go to wolf camp, rupture twice, autoattack big wolf, point in Vorpal Spikes.
Pop a potion, rupture Golem, keep spamming rupture and autoattacking. Also, position yoursel so your vorpal spikes hit both the little lizards as well. This gives you a big health boost when you kill them, letting you keep decent health throughout golem, point in rupture.
Go to Golems, rupture+attack.
Lizard, spam rupture, smite lizard.
Gank!
At above 6, you can get Dragon, with Smite/Feast and pots.

Absolutely not viable, he's easily one of the best farmers/laners in the game and can deny exp/gold very well. Would be a HUGE waste to jungle with him.

What Le Shirrif said is basically how I do jungle cho. Try starting with vorpal first though and see how you like it.

He is a really good laner. Lot of teams I saw from watching a ESL tourny were actually doing cho bot with a roaming support. He does great top too.

you start with vorpal spikes, not rupture, and you dont need to start with armor + pots b/c of cho's passive/regen.. i personally start with a ruby crystal first, and go early catalyst first, starting at wraiths, lvl 1 vorpal spikes, smite big wraith, auto attack rest to death, then to wolves, lvl 2 -> rupture... smite back up soon, do blue golem, smite is back up... go from there

You can start with VS or Rupture. I've tried both. Whilst they both work, Rupture results in you arriving at blue buff with more health. Which is good. And you can managed without Cloth armour, but you have less health, again, adding risk. It's like saying most junglers don't need Smite. It's true, but adds risk, and slows your run significantly.

Just did jungle Cho today. Went 10-2-17 in the end, but thats hardly relevant.
I went tank Cho, since my team was pretty squishy.

Masteries:
1-21-8
http://leaguecraft.com/masteries/001...03140000000000

Runes:
I use my Shaco runes. Not the best choice, but its the rune page I use for all of my junglers.

3 Flat Health Quintessences
9 Armor Pen Marks (should be substituted with attack speed if you are going to dedicate to jungle Cho)
9 Flat Armor Seals
9 Magic Resist per Level Glyph

Items:
Core Items:
Cloth Armor + 5 Pots
Cloth Armor into Aegis of Legion
Merc Treads
Banshee's Veil
Guardian Angel

The other 2 slots go for different defensive items.

Lot of Casters:
Force of Nature
Abyssal Scepter

Lot of DPS:
Sunfire Cape (this is generally better than Thornmail imo)
Frozen Heart

Summoner Spells:
Ghost + Smite
Always take Smite if you are going to jungle with anyone.

I start with Vorpal Spikes. Start at mana golem if you are protected or if the other team isn't going to gank you at blue. Start at double golems or wraiths if you are feeling paranoid.

Skilling Order:

EQQW or EQEW or EQEQ

As you see, Cho'gath is really versatile, and any build can work with jungle Cho. Good luck, and have fun!